The Sub-Cellular Localization of WRAP53 Has Prognostic Impact in Breast Cancer

WRAP53 protein controls intracellular trafficking of DNA repair proteins, the telomerase enzyme, and splicing factors. Functional loss of the protein has been linked to carcinogenesis, premature aging and neurodegeneration. The aim of this study was to investigate the prognostic significance of WRAP53 protein expression in breast cancer. A tissue microarray was constructed from primary breast tumors and immunostained by a polyclonal WRAP53 antibody to assess the protein expression pattern. Two different patient cohorts with long term follow-up were studied; a test- and a validation set of 154 and 668 breast tumor samples respectively. Breast cancer patients with tumor cells lacking the expression of WRAP53 in the nucleus had a significantly poorer outcome compared to patients with tumor cells expressing this protein in the nuclei (HR = 1.95, 95%CI = 1.09–3.51, p = 0.025). Nuclear localization of WRAP53 was further shown to be an independent marker of prognosis in multivariate analysis (HR = 2.57, 95%CI = 1.27–5.19, p = 0.008), and also significantly associated with better outcome in patients with TP53 mutation. Here we show that the sub-cellular localization of the WRAP53 protein has a significant impact on breast cancer survival, and thus has a potential as a clinical marker in diagnostics and treatment.     

Rat erythrocyte glycophorins can be isolated by the lithium diiodosalicylate method used for other glycophorins.

1. The lithium diiodosalicylate/phenol method, widely employed for the isolation of membrane sialoglycoproteins (glycophorins) from mammalian erythrocytes, was applied for the first time to the purification of homologous glycoproteins from rat erythrocyte membranes. 2. The resulting preparations showed to be composed of four components, fractionated on SDS-PAGE. All four were positive for periodic acid-Schiff's reagent stain, the two largest of them being major. 3. Isolated rat glycophorins accounted for 60% of the ghost sialic acid and 1.5% of their protein. The presence of O-acetyl groups was confirmed in one-third of the sialic acid residues. 4. The molecular masses of the four glycophorin components were determined by a method which takes into account the anomalous mobility of glycoproteins on SDS-electrophoresis. Estimated values thus obtained for the actual molecular masses were 74, 32, 25 and 17 kDa.     

Age-related diffuse chronic telogen effluvium- type alopecia in female squirrel monkeys (Saimiri boliviensis boliviensis)

We investigated the diffuse alopecia affecting some female squirrel monkeys (Saimiri boliviensis boliviensis) housed in a breeding facility. We randomly selected 100 female and 10 male animals and performed a complete physical exam and a hair assessment on all animals; blood tests, trichograms, hair density; and skin biopsies in representative cases; and a dominance behavioral assessment of 50 animals. Hair coat was normal in 35 female monkeys and all 10 male animals. Of the 65 females with diffuse alopecia, 17 had mild, 22 moderate, and 26 severe hair loss. The alopecia group had a mean age of 9.6 +/- 0.6 years, whereas that of the normal group was 4.7 +/- 0.6 years (P < 0.05). The parity in the alopecia group was 4.2 +/- 0.6 but 2.0 +/- 0.6 (P < 0.05) in the normal group. There were no statistically significant differences in body weight, hemoglobin, blood urea nitrogen, serum glucose, liver aspartate aminotransaminase, or free thyroxine. The trichogram demonstrated 20.8% +/- 1.6% (mean +/- standard error) of telogen hairs in the alopecia group compared with 9.5% +/- 2.8% of the control group (P < 0.05). The hair density in the alopecia group was 52.8 +/- 4.1/cm2 and 79.6 +/- 14.3/cm2 in the control group. Skin biopsies in affected monkeys demonstrated increased telogen follicles, with no fibrosis or inflammation. There were no statistically significant differences in the dominance behavioral analysis. The findings are consistent with chronic telogen effluvium (CTE). A number of organic, behavioral, and dominance-related stress causes of CTE were excluded. CTE appears to be predominantly age-related in this population. CTE in female squirrel monkeys may serve as an animal model for human diffuse alopecia.     

Translational repression of a C. elegans Notch mRNA by the STAR/KH domain protein GLD-1

In C. elegans, the Notch receptor GLP-1 is localized within the germline and early embryo by translational control of glp-1 mRNA. RNA elements in the glp-1 3'untranslated region (3' UTR) are necessary for repression of glp-1 translation in germ cells, and for localization of translation to anterior cells of the early embryo. The direct regulators of glp-1 mRNA are not known. Here, we show that a 34 nucleotide region of the glp-1 3' UTR contains two regulatory elements, an element that represses translation in germ cells and posterior cells of the early embryo, and an element that inhibits repressor activity to promote translation in the embryo. Furthermore, we show that the STAR/KH domain protein GLD-1 binds directly and specifically to the repressor element. Depletion of GLD-1 activity by RNA interference causes loss of endogenous glp-1 mRNA repression in early meiotic germ cells, and in posterior cells of the early embryo. Therefore, GLD-1 is a direct repressor of glp-1 translation at two developmental stages. These results suggest a new function for GLD-1 in regulating early embryonic asymmetry. Furthermore, these observations indicate that precise control of GLD-1 activity by other regulatory factors is important to localize this Notch receptor, and contributes to the spatial organization of Notch signaling.     

Activation of RAT erythrocyte phosphofructokinase by AMP and by non-physiological concentrations of Cyclic AMP

Summary Cyclic AMP (300µ m) activates phosphofructokinase from dialyzed haemolysates of mature rat erythrocytes. The main conclusions are: a) Cyclic AMP, at pH 7.1 and low concentrations of fructose-6-phosphate, is able to reverse the inhibition produced by different amounts of ATP (up to 1.5mm). b) The cyclic nucleotide is a positive allosteric effector of the enzyme as shown by the displacement of sigmoidal fructose-6-phosphate saturation curve to hyperbolic kinetics in the presence of inhibitory concentrations (1.5mm) of ATP. c) Cyclic AMP has no significant influence as deinhibitor of phosphofructokinase either at pH 7.1 and non-inhibitory levels (0.25mm) of ATP or at pH 8.1 and inhibitory (1.5mm) of non-inhibitory (0.25mm) concentrations of ATP. Similar conclusions were obtained with 300µ m AMP but not at a lower concentration (3µ m) with both nucleotides.The comparison of cyclic AMP results with those obtained under similar concentrations of AMP suggest that cyclic AMP is really only an in vitro modulator of the enzyme from rat erythrocytes, presumably at an AMP regulatory site, since non-physiological concentrations are required to act as deinhibitor.